Ignition system and generator therefor



June 23, 1953 s. E. MILLER 2,643,274

IGNITION SYSTEM AND GENERATOR THEREFOR Filed Jan. 28, 1950 5 Sheets-Sheet l INVE O'E. SIDNEY EL. lLLEE ATTORNEY June 23, 1953 s. E. MILLER IGNITION SYSTEM AND GENERATOR THEREFOR 5 Sheets-Sheet 2 :v 2 Sm v E m I E u m N ma m z WY 4 w 1E A N 6w. m V l s U u I W km 0W 0W. QT I mm, m w| Q I um w ow 1 I (m 3k i, B x All mm mv T June 23, 1953 s. E. MILLER 2,643,274

IGNITION SYSTEM AND GENERATOR THEREFOR Filed Jan. 28, 1950 5 Sheets-Sheet 5 F 24nc 23 24b 24,0. 245 23 y key I 4-... 2| 2o 20 20 N s N 5 N l 8 la 22 22 22 J? '9 A m INVENTOR- SlDNE-Y E.- MIL-LEE S. E. MILLER IGNITION SYSTEM AND GENERATOR THEREFOR June 23, 1953 5 Sheets-Sheet File d Jan. 28, 1950 INVENTOE. '5. SIDNEY E..MILLE12 BY%%% ATTORNEY.

June 23, 1953 s. E. MILLER 2,643,274

IGNITION SYSTEM AND GENERATOR THEREFOR Filed Jan. 28, 1950 5 Sheets-Sheet 5 INVENTOE. SIDNEY E. MILLER ATTO'EN EK Patented June 23, 1953 IGNITION SYSTEM AND GENERATOR THEREFOR Sidney E. Miller, Suffield, Conn., assignor to American Bosch Corporation,

Springfield,

Mass., a corporation of New York Application January 28, 1950, Serial No. 140,991

17 Claims.

vThis invention relates to a new and improved low tension breakerless ignition system for large, relatively low speed engines, and a new and improved generator for said system.

An object of the invention is to provide an ignition system of the type set forth which employs low tension distribution and provides a long duration, multiple spark output.

-Another object of the invention is to provide anew and improved generator for an ignition system of the type set forth.

Another object of the invention is to provide a low tension ignition system and a generator therefor, which employ no moving contacts, slip rings, brushes, commutators or other devices which might cause an open arc, and, therefore, is practically explosion proof.

Another object of the invention is to provide an ignition system of the type set forth in which the length of high tension lead may be reduced to a minimum.

Other objects and advantages of the invention will be apparent from the following description taken in connection with the accompanying drawings. It will b understood that changes may be made in the details of construction and arrangement of parts without departing from the scope of the invention as expressed in the accompanying claims, as the preferred form of the invention has been given by way of illustration only.

Referring to the drawings:

Fig. 1 is a diagrammatic view of an ignition system embodying the invention;

Fig. 2 is a longitudinal sectional view of the generator employed in the system;

Fig. 3 is a sectional view. taken on line 33 of Fig. 4 is a sectional view taken on line 4-4 of Fig. 2, looking in the direction of the arrows;

Fig. 4A is an end View of the generator;

Figs. 5 to '7 inclusive are sectional views, on an enlarged scale and illustrating the flux reversal operation of the generator of Figs. 2, 3 and 4; and

Fig. 8 is a plan view of the preformed winding or coil employed in the stator.

Referring more particularly to the drawings, wherein similar reference characters designate corresponding parts throughout, the ignition system is shown by way of illustration only in Fig. l as applied to a double or dual ignition engine, but itwill be understood that it may also be applied to either double or single ignition engines.

In Fig. 1 there is shown the generator stator 2 I0 having the tooth II between slots I2 and I3 and on tooth II is provided generating winding I4 which is connected at one end by lead I5 to ground I6 and at its opposite end by lead I! to transformer I8.

A rotor I9 is provided which includes a pair of poles 20 and 2I adjacent its periphery and between said poles 20 and 2| is provided a bar shaped permanent magnet 22 which is carried by the rotor I9 for rotation therewith.

Instead of the permanent magnet 22, wound field coils or other means providing a pair of magnetic poles on the rotor capable of providing axial excitation of the rotor could be employed.

Between stator I0 and rotor I9, and concentric with said stator is provided inductor or flux reversing ring or rotor 23. This rotor 23 is of squirrel cage form and consists of a series of spaced lamination stacks 24 of electrical sheet steel, each of the stacks being separated from the others by non-magnetic material.

The flux reversing or chopping rotor 23 is preferably rotated in the same direction as rotor I9 and also preferably at about five times the speed of rotor I9 which is driven at engine speed for a two-stroke cycle engine or one-half engine speed for a four-strok cycle engine, although said flux reversing rotor 23 could be so constructed and arranged as to work satisfactorily while rotating in the opposite direction from rotor I9 or even if-not rotated. Also, either the stator II] or rotor I9 could be stationary instead of rotor 23 or rotated in the same direction or otherwise.

The number of teeth I I and windings I4 which are provided on stator I0 depend upon the number of cylinders in the engine on which the system is employed and the spacing of said teeth II and windings I4 can be equal or not as desired for timing of a particular engine although normally such teeth II and coils I4 are equally spaced.

'In the system shown in Fig. 1 for dual ignition, the transformer I8 includes the primary 25 grounded at 26 and a double or two-section secondary winding having the sections 2'! and 28 each connected to one of the spark plugs 29 and 30 respectively. In this system the voltage limiting gaps or safety gaps SI and 32 are provided in the transformer housing.

In Figs. 2, 3 and 4 is shown an embodiment of the generator designed for use with an eight cylinder engine. In this embodiment the stator I0 is provided with eight equally spaced teeth II, each provided with a set of slots I2 and I3 on the opposite sides thereof, each of which slots is lined with an insulating paper and a preformed coil 33 is placed in each set of slots, and one of the leads 3d therefrom is connected to terminal posts 35 and the other lead 36 is connected to ground.

Rotor i9 is mounted on shaft 31 for rotation therewith, which shaft is journalled in bearings 38 and 39 and adapted to be driven by the en- I gine.

Stator I0 is retained in position between end plates 40 and M by studs 42.

Ring gear 53 is secured to end plate 481 bybolts or the like M. Carrying arm 35 is keyed to shaft 3'! and supports the two planetary gears 46 and 41 which mesh with ring gear 33 and sun gear it which, in turn, is --mounted onfl'ux reversin ring 23 which is journalled in bearings 49 and 50 on shaft 31.

Magnet rotor l9 comprises a pair of end plates 5| and. 52 pressed on shaft 3'! and supporting therebetween bar magnet 22 and counterweight 23. Pole shoes 29 and 2! are also carried by rotor l9. Damper ring 53 surroundsmagnet 22.

.Flux reversing ring'23 comprisesa pair of end plates 56 and 55. which are 'journalled on the shaftand between which are supported the lamb-- nation stacks 2 3 which each haverivets 56;extending. therethrough which rivets have their opposite .endseXtendingthr-ough rings 5 and 58' afterwhich-the ends-of the rivets are headed-- over andv this entire unit is supported bytheend'so plates by screws orthe-like. 7 7

Baffle 59 and oil seal fit-separate the gear compartment from the electrical compartment.

Inoperation, shaft 31 is driven by-the engine and. said-.shaft,.in-turn, rotates rotor i9- and 55 through the planetarygearing rotates flux-reversing..ring 23 as previously described.--

The -fiux reversing system is shownin detailirLFigs...5, Sandi;

In Fig... 5, lamination stack zfla is-just apiO prQachingLbutsIightly spaced from tooth i i and lamination stacks Z ta and Mbare-aligned-with poleshoes ,2!) and 2Iof rotor 19-. Then-the flux will follow the-path shown by the arrows inFig.-'5.-

As the rotor I9, and pole shoes 2:: and 2! move-- slightly and lamination stack 25a of flux reversing ring 23 moves-into alignment'with the edge of tooth I Lthefiux will-pass through lamination stacks 24a andl lb and follow the pathshownby" the arrowsinFig.6.--

vAs .the rotor 19 and lamination stack -26a of fiuxereversingring. move slightly beyond the positionshown inFig. 6, the fluxwill follow the path shown in Fig- .'Z

'IYhis.. change offlu-x pathrapidly-reverses the flux through'tooth' i l between the windings and this rapid reversal of fluxproduces the potential- Oroutputofthe generator.

Itewillbe seen from the foregoing that becauseof -the flux reversing --Ill'l-g--- Z3 a more rapid flux 60 reversal is obtained which is necessary for good" output at low speeds and that yetonly a-single magnetis employed.

Also, this system results in multiple spark igni tion vvhich'is advantageous for the firing of lean mixtures. l 1

Instead of the flux-reversing ring '23 as-shown in-Figs b -to 7 inclusive, this ring could be ernployed as a flux chopping'o'r' pulsing unit in which nonug reversai is effected, but instead said ring would'vary the flux from Zero to a maximum H value with constant polarity. In such a' construction the" rotor I 8 will be essentially unipolar and excited either by integral magnets or remote 4 axial excitation, employing either permanent magnets or wound field coils.

Furthermore it will be noted that the low tension system of the present invention lends itself to complete shielding for making an explosion proof construction for use in installations such as gas fields where combustible materials may be present. v j j K From the foregoing it will be seen' that I have provided new and improved means for obtaining all of the objects and advantages of the inveno 'l lavingdescrib'ed my invention, 1 claim:

"1';"In a device of the character described, a statonha'ving' multiple tooth sections with an intermediate toothof each section having a generating co'ilfla magnet rotor having a pair of magnetic polesand a fiux reversing ring between said stato'rjand said magnet rotor, said flux reversingring having at least one pair of magnetic bridges adapted to effect a reversal of flux as rotation is effected between said ring and said statorand rotor. p

2:* Ina device of the character described, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil,--a magnet rotor havinga pair of magnetic'poles, a flux reversing 'ring between. said stator and said magnet rotor and "means for effectin relative rotation between saidind'uctor ringand said magnet rotor and stator; said flux reversing ring having at least one pair of mag. netic bridges adapted to effect a reversalof'fiux as rotation is effected between'said ring and said stator and rotor. i

3.- In'a device of thecharacter describedfa' stator-havingmultiple tooth sections with an intermediate tooth of each sectioirhavin'g agenerating coil, a magnetrctor havin'g'a' pair" of magnetic poles; means for-rotating s'aid"magnet"" rotor relative to said stator,"afiuxreversing'ring between said stator and said magnet rotor"'and means for -rotating said inductor ring relative to said-stator, said fiux reversing r'ing'ha'vin'g at" least onepa-ir of magnetic bridgesa'dap'ted' to effect a reversal of flux as rotationis effected" between said ring and said stator and rotor."

4. In a device of the character" described, a stator having multiple. tooth'sections' with an intermediate tooth of each section'havingagencrating coil, a shaft, a magnet 'rotonhaving, a" pair of magnetic poles adapted to be rotated by" said shaft and a flux reversing "ring between" said stator and said magnetfrotor and adapted to" be rotated by said shaftysaid fiuxreversing ring' having at-least "on'e pa'ir' or magnetic bridges adapted to effect a-"reversal "offlux'as rotation" is effected between said ring and "said stator and rotor. 5. In a device of" the'characterdescribed, "a stator having multiple tooth sections with an intermediate tooth'of each section having a generating coiL'a-magnet rotor'havin "a pair of magnetic poles and aflux'reversing ring between said stator and said magnet rotor," a shaft adapted to rotate said magnet rotor and a plane 'tary gearing rotated by said shaft and adapted" to rotate said inductoru'ing, said "flux "reversing ring having at: least one pair of magnetic bridges 0 adapted to effect a reversal of fiux"as"rotati'o'n' and'said-stator and is effected betweensaidrin rotor. g g I j 6. In 'a device of the character described, a stator having multiple tooth sections with an intermediate tooth of each section having agenerating coil, a magnet rotor and a flux reversing ring between said stator and said magnet rotor, and a single pair of magnetic poles on said magnet rotor, said flux reversing ring having at least one pair of magnetic bridges adapted to eifect a reversal of flux as rotation is effected between said ring and said stator and rotor.

7. In a device of the character described, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil, a magnet rotor, a flux reversing ring between said stator and said magnet rotor and means for effecting relative rotation between said inductor ring and said magnet rotor and stator, and a single pair of magnetic poles on said magnet rotor, said flux reversing ring having at least one pair of magnetic bridges adapted to effect a reversal of flux as rotation is effected between said ring and said stator and rotor.

8. In a device of the character described, a I

stator having multiple tooth sections with an intermediate tooth of each section having a generating coil, a shaft, a magnet rotor adapted to be rotated by said shaft and a flux reversing ring between said stator and said magnet rotor and adapted to be rotated by said shaft, and a single pair of magnetic poles on said magnet rotor, said flux reversing ring having at least one pair of magnetic bridges adapted to effect a reversal of flux as rotation is efiected between said ring and said stator and rotor.

9. In a device of the character described, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil, a shaft, a magnet rotor having a pair of magnetic poles adapted to be rotated by said shaft and a flux reversing ring between said stator and said magnet rotor and adapted to be rotated by said shaft at a speed considerably greater than the speed of rotation of said magnet rotor, said flux reversing ring having at least one pair of magnetic bridges adapted to effect a reversal of flux as rotation is effected between said ring and said stator and rotor.

10. In a device of the character described, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil, a magnet rotor having a pair of magnetic poles and a flux reversing ring between said stator and said magnet rotor, a shaft adapted to rotate said magnet rotor and a planetary gearing rotated by said shaft and adapted to rotate said inductor ring at a speed considerably greater than the speed of rotation of said magnet rotor, said flux reversing ring having at least one pair of magnetic bridges adapted to effect a reversal of flux as rotation is effected between said ring and said stator and rotor.

11. In an internal combustion engine ignition system, a generator driven by the engine and having a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil, a magnet rotor having a pair of magnetic poles and a flux reversing ring between said stator and magnet rotor, said flux reversing ring having at least one pair of magnetic bridges adapted to efiect a reversal of flux as rotation is eiTected between said ring and said stator and rotor and adapted to produce by the reversal of flux therebetween an output consisting of a group of impulses in rapid succession at each firing period of the engine with a period of substantially zero generation between successive groups of impulses, a transformer having its primary connected to the output terminals of said generator and a load circuit connected to the secondary of said transformer and including spark gap means for said engine periodically energized by said groups of impulses.

12. In a device of the character described adapted to supply ignition pulses to each of the cylinders of an internal combustion engine, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil and having a tooth or pole and coil for each engine cylinder, a magnet rotor carrying a single pair of magnetic poles and a flux reversing ring between said stator and magnet rotor, said fiux reversing ring comprising a plurality of spaced lamination stacks forming magnetic bridges and adapted to reverse the flux path through said stator tooth or pole.

13. In a device of the character described adapted to supply ignition pulses to each of the cylinders of an internal combustion engine, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil and having a tooth or pole and coil for each engine cylinder, a magnet rotor carrying a single magnet and a pair of magnetic poles and a flux reversing ring between said stator and magnet rotor, said fiuxreversing ring comprising a plurality of spaced lamination stacks forming magnetic bridges and adapted to reverse the flux path through said stator tooth or pole, and means for effecting relative rotation between said stator and magnet rotor.

14. In a device of the character described adapted to supply ignition pulses to each of the cylinders of an internal combustion engine, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil and having a tooth or pole and coil for each engine cylinder, a magnet rotor carrying a single magnet and having a pair of magnetic poles and a fiux reversing ring between said stator and magnet rotor, said flux reversing ring comprising a plurality of spaced lamination stacks forming magnetic bridges and adapted to reverse the flux path through said stator tooth or pole, and means for effecting relative rotation between said stator and said flux reversing ring and magnet rotor.

15. In a device of the character described adapted to supply ignition pulses to each of the cylinders of an internal combustion engine, a stator having multiple tooth sections with an intermediate tooth of each section having a gen erating coil and having a tooth or pole and coil for each engine cylinder, a magnet rotor carrying a single magnet and having a pair of magnetic poles and a flux reversin ring between said stator and magnet rotor, said flux reversing ring comprising a plurality of spaced lamination stacks forming magnetic bridges and adapted to reverse the flux path through said stator tooth or pole, and means for effecting rotation of said flux reversing ring relative to said stator and magnet rotor.

16. In a device of the character described adapted to supply ignition pulses to each of the cylinders of an internal combustion engine, a stator having multiple tooth sections with an intermediate tooth of each section having a generating coil and having a tooth or pole and coil for each engine cylinder, a magnet rotor carrying a single magnet and having a pair of magnetic poles and a flux reversing ring between said stator and magnet rotor, said fiux reversing ring comprising a plurality of spaced lamination w re stacks forming magnetic bridges and adapted to reverse th flnX- path through said'stator tooth or poieg a shaft for rotating said magnet rotor and planetary gearing foreffecting rotation of said flux reversing ring upon rotation of said shaft. 5 l

17.'In a device of the character described adapted-to supply ignition pulses to each of the cylinders of an internal combustion engine, a'

stator having multiple tooth sections with an intrr'nediatetooth of each section having a generating coil and havin a tooth or pole and coil foreac'h engine cylinder, a magnet rotor carrying asinglemagnet and having a pair of magnetic poles and a flux reversing ring between said stator and magnet rotor, said flux reversing ring comprising a plurality of spaced lamination stacks forming magnetic bridges and adapted to reverse the flux path through said stator tooth or pcl'e, a shaft for rotating said magnet rotor and planetary gearing for effecting TOtQItiOHTOf said flux reversing ring at a speed considerably greaterthan the speed'of rotation of saidma gnet':

rotor.

' SIDNEY E. MILL References Cited in the file of this patent,

UNITED STATES PATENTS Number Name Date 730,673 Lunt June 9', 1903 958,754 Mueller May 24, 1910' 1,021,219 Thomson Mar. 26, 1912 1,171,134 Neuland Feb. 8, 1916 1,266,302 Neuland May 14, 1918. 1,712,719 schon May 14,. 1929 1,808,435 Punga June 2, 1931 1,823,217 Sparkes Sept. 15, 1931- 2,071,573. Randolph Feb. 23, 1937. FOREIGN PATENTS I Number Country Date 528,753 Great Britain Nov; =6, 1918. 

